In situations where volume computation should not occur, you can define gaps in the materials.
A gap can be used where there is one gap in the material, such as a bridge location. Gaps can also be used in multiple locations, where there are non-contiguous pockets of a material along the length of a corridor.
Gaps are defined in the Sample Line Group Properties, Material List tab. For more information, see Material List Tab (Sample Line Group Properties Dialog Box).
Run In and Run Out Distances For Gaps
Gaps can have run in and run out distances which act as transition areas between materials. By default the gaps have run in and run out values of zero. No material is interpolated beyond the gap stations, as shown in the following illustration.
If marsh material is present between station 2+00 and 3+00 with short transitions before and after, you can specify run in and run out instead of adding more sample lines, as shown in the following illustration.
The run in for the material is defined in the first gap, and the run out for the material is defined in the second gap. Therefore, the first gap would have a run in of 50, and the second gap would have a run out of 75.
If you want to have tighter control on the run ins and run outs, you can set smaller values or keep the default of zero.
Defining Gaps for Pockets of Material
In the following example, three materials are defined: Cut, Fill, and Marsh material. The Marsh material exists only at the hatched areas in the illustration. All three materials must be added into one material list because the cumulative cut/fill calculations should include all three types.
For this example, you would add 3 gaps (as represented by numbers 1, 2, and 3 in the illustration) with appropriate run ins and run outs for material transitions. In the material list the gaps should only be applied to Marsh material and not for the materials named Cut and Fill.
To define gaps for a material list
- Select a sample line.Click Sample Line tab
Modify panelGroup Properties
.At the Command prompt, enter EditSampleLineGroupProperties. - Click the Material List tab.
- If you have not yet added materials to the sample line group, add the required materials. For more information, see Material List Tab (Sample Line Group Properties Dialog Box).
Note
You can add material list definitions on the Material List tab, or you can use the Compute Materials command. for more information, see Generating Material Lists.
- At the the
Material List level, click the Gap column. The Define Gaps dialog box is displayed. - Use Define Gaps dialog box to define a list of gaps along the alignment. In this dialog box, you define the start and end stations of the gaps for the entire material list. In Step 7 you use the Apply Gaps dialog box to control the gaps for each individual material.
- Click OK to return to the Material List tab.
- At the
Material level, click the Gap column. The Apply Gaps dialog box is displayed. - In the Apply Gaps dialog box, clear the Apply Gaps check box for any material for which gaps should not be applied. For example, if Cut or Fill material is found throughout the length of the alignment with no gaps, clear the Apply check boxes for those gaps.
- For materials for which you want to apply gaps, keep the Apply check box selected and define the Run Out and Run In distances. These distances apply to the material before and after the gaps.
In the following illustration, the green areas 1 and 2 represent gaps in the material (5). Gap 1 does not have a run out distance. However, Gap 1 has a run in distance of 40m as represented by the red area number 3.
Gap 2 has a run out distance of 75m as represented by the red area number 4.
These gaps would be defined as follows:
- Start Station: 0+000
- End Station: 0+300
- Run Out Distance: 0.00
- Run In Distance: 40.00
- Start Station: 0+700
- End Station: 1+200
- Run Out Distance: 75.00
- Run In Distance: 0.00